1. Field of Invention
The present invention relates to a reproduction device and a reproduction method for contents protected by copyright, and a recording medium having recorded thereon data used for the same. More particularly, the present invention relates to a reproduction device and a reproduction method for multimedia-type contents protected by the copyright, and a recording medium having recorded thereon data for the same.
2. Description of Related Art
In a conventional contents distribution system using Digital Rights Management (DRM) system, streaming-type contents such as music or a movie are primary objects for the distribution. For the streaming-type contents, a model (hereinafter referred to as a rights management model) to manage the copyright is already being established. Hereinafter, a reproduction procedure of the contents according to the conventional rights management model will be described.
Initially, a procedure at a start of reproduction will be explained. First, a contents reproduction device determines whether or not a use of contents is possible by referring to a license associated with the contents. Here, a license is information required for a contents use, and information indicating a use condition for the contents. If it is determined that a use is possible, the reproduction device locks the license. Then, the reproduction device extracts a decryption key, of the contents, which is contained in the license. Next, the reproduction device uses the extracted decryption key to decrypt the contents, and reproduces the contents.
Next, a procedure performed when terminating a reproduction will be described. First, the reproduction device updates content of the license in accordance with a use situation at an end of the reproduction. For example, the reproduction device reduces a remaining use time, or the like, thereby updating the contents of the license. Then, the reproduction device releases the license lock.
As described above, the conventional reproduction device locks a license at a beginning of a reproduction, updates the license in accordance with a use situation and releases the lock at an end of the reproduction. Therefore, the license is updated each time contents are used to prevent illegal use of the contents.    [Patent Document 1] Japanese Laid-Open Patent Publication No.